is exporting a source of productivity spillovers?
TRANSCRIPT
CAEPR Working Paper #2006-012
Is Exporting a Source of Productivity Spillovers?
Roberto Alvarez
Central Bank of Chile
Ricardo Lopez Indiana University Bloomington
September 26, 2006
This paper can be downloaded without charge from the Social Science Research Network electronic library at: http://ssrn.com/abstract=932943.
The Center for Applied Economics and Policy Research resides in the Department of Economics at Indiana University Bloomington. CAEPR can be found on the Internet at: http://www.indiana.edu/~caepr. CAEPR can be reached via email at [email protected] or via phone at 812-855-4050.
©2006 by Roberto Alvarez and Ricardo Lopez. All rights reserved. Short sections of text, not to exceed two paragraphs, may be quoted without explicit permission provided that full credit, including © notice, is given to the source.
Is Exporting a Source of Productivity Spillovers?*
Roberto Álvarez†
Ricardo A. López‡
September 2006
Abstract
This paper investigates whether exporting generates positive productivity spillover effects on
other plants operating in the same industry and whether exporting affects productivity of
plants in vertically related industries. Using plant-level data from Chile we find that exporters
improve productivity of their local suppliers but not of plants that purchase intermediate
inputs from them. We also find evidence of horizontal spillovers from exporting. Exporting by
foreign-owned plants generates positive spillovers in all directions: to their suppliers,
customers, and to other plants in the same industry. Domestic exporters increase productivity
of their suppliers and, to a lesser extent, that of plants in the same sector.
JEL: F10, F23, 03, 054
Keywords: exporting, spillovers, productivity, vertical linkages, Chile
* We would like to thank Hadi Salehi Esfahani, Gerhard Glomm, Holger Görg, Kim Huynh, Beata S. Javorcik, Renata Kosova, Volodymyr Lugovskyy, Mahmut Yasar and seminar participants at Illinois, Indiana, Memphis, the Midwest International Economics Meeting at Kansas, the International Industrial Organization conference at Northeastern University, and the European Trade Study Group Conference at the University of Vienna for very helpful comments and suggestions. We also thank Jean Morrison for proofreading and editing the manuscript. † Central Bank of Chile. E-mail: [email protected]. ‡ Corresponding Author. Department of Economics, Indiana University. Address: Wylie Hall Room 105, Indiana University, Bloomington, IN 47405, U.S.A. Telephone: +1-812-856-1466. Fax: +1-812-855-3736. E-mail: [email protected].
1
1. Introduction
Many people believe that exporting firms generate knowledge about technologies and foreign
markets which can be used by other exporters and non-exporters in ways that increase their
productivity. Surprisingly, we know little about the effects of exporting on other firms’
productivity and whether foreign-owned exporters, domestic exporters, or both, are the ones who
generate spillovers. Using data for Chilean manufacturing plants, we investigate whether exporting
by both foreign-owned and domestic plants generates positive productivity spillover effects on
plants operating in the same industry and in vertically related industries.
Most of the previous literature studies the effect of general exporting activity on the
probability of exporting and export performance (e.g. Aitken, et al., 1997; Clerides, et al., 1998;
Barrios, et al., 2003; Bernard and Jensen, 2004a) but, with only few exceptions (e.g. Clerides, et
al., 1998; Javorcik, 2004; Girma et al., 2004; Görg and Hijzen, 2004), it has overlooked the effect of
exporting on productivity. Moreover, no study exists looking at productivity spillovers from
exporting by domestic plants.
In general, scholars find very little support for the idea that exporting increases the
probability of exporting and export performance of other firms. We believe that only looking at
the impact of spillovers on export performance may be misleading. Since there are sunk-entry costs
to export markets,1 it may be difficult to observe general exporting activity inducing entry to
export markets unless spillover effects are big enough to compensate for these entry costs.
Moreover, most of the studies look for intra-industry spillovers and ignore the potential linkages
from buyers of output to suppliers of inputs and vice versa.
1 See Roberts and Tybout (1997), and Bernard and Jensen (2004a).
2
From a policy point of view, it is important to analyze whether these spillover effects exist
or not. The existence of spillovers from exporting has been traditionally used as a justification for
the adoption of export promotion programs. Many countries in the world have encouraged exports
with the idea that they might fuel economic growth. Researchers have investigated whether these
export promotion programs are justified by testing the existence of learning-by-exporting.2 But
from a policy perspective, the relevant question is whether exporting generates spillovers to other
firms. The existence of learning by exporting itself is not necessarily a justification for export
promotion unless it can be shown that these learning effects spill over the rest of firms.
Our paper is related to the economic development literature which argues that export
activity may generate demonstration effects or provide new technologies that are not available for
domestic producers.3 This paper is also consistent with microeconomic evidence documenting that
exporters are more productive than non-exporters. Starting with the study by Bernard and Jensen
(1999) for the U.S., scholars have found evidence of productivity differentials in favor of
exporters.4 In the case of Chile, Álvarez and López (2005) show that after controlling for size and
foreign capital participation, exporters are 19 percent more productive in terms of total factor
productivity than non-exporters. These differentials make learning by domestic firms from highly-
productive exporters potentially important.
We make several contributions to the empirical literature. First, we test for the existence of
spillovers from exports on plant productivity. Second, we not only consider spillovers from plants
in the same industry, but also explore the role of vertically linked activities. Third, we analyze if
2 See recent surveys by López (2005), Greenaway and Kneller (2005), and Wagner (2005). 3 Some scholars, however, are more skeptical about the existence of these spillover effects. See Rodrik (1999), and Panagariya (2000). 4 See, for example, Bernard and Wagner (2001) for Germany; Isgut (2001) for Colombia; and Baldwin, and Gu (2003) for Canada. Wagner (2005) surveys the empirical strategies and results of 45 studies for 33 countries. He concludes that the evidence is robust in terms that exporters are more productive than non-exporters. Interestingly, most of these studies reveal that firms self-select in international markets while exporting does not necessarily have a positive effect on firm productivity (see also López, 2005).
3
there is a different impact between domestic and foreign-owned plants’ exports. By making this
distinction, we investigate if spillovers, as other authors have claimed, are mostly provided by
multinational enterprises. And fourth, we address several estimation issues that have plagued
previous studies. In particular, unlike previous works, we take into account the possible
endogeneity of our spillover variables by employing IV estimation methods. We construct three
different types of sector-level real exchange rates and use them as instruments. Our identification
assumption is that real exchange rate is correlated with industries export orientation, but it does
not affect plants productivity directly. In addition, following Aitken et al. (1997), we control for
general concentration of economic activity at region and industry level to make sure that we are
effectively capturing the impact of export activity, and not the impact of agglomeration or specific
advantages of some locations.
Using information for Chilean manufacturing plants from 1990 to 1999, we find strong
support for the view that exporters improve productivity of their local suppliers. We also find
evidence of horizontal spillovers from exporting but not from exporters to their customers.
Exporting by foreign-owned plants generates positive spillovers in all directions: to their suppliers,
customers, and to other plants in the same sector. Our finding that domestic exporters increase
productivity of their suppliers and, to a lesser extent, that of plants operating in the same industry
indicates that positive spillovers are not only associated with a larger presence of multinational
exporters, but also with exporting activity of domestic firms. Thus, we conclude that researchers
could have underestimated the role of domestic exporters in generating positive effects on other
firms’ productivity.
4
2. Spillovers from Exporting
The presumption that spillovers from exporting exist has been traditionally used as a
justification for the adoption of export promotion programs. Several arguments for why exporting
may generate these spillovers have been proposed. For example, consider a firm entering in a new
market or developing a new product for foreign markets; it faces several costs such as promotional
investments, making contacts with new clients, and technological innovation expenditures. Once
the firm achieves its objective, however, there is no impediment for other firms to enter this
market or imitate the new product without also paying these costs. This positive externality
suggests that investment in opening new markets and developing new products may be lower than
the socially optimal level (Westphal, 1990). Other authors argue that exporters tend to adopt
efficient and competitive management styles, and training of a higher quality of labor which may
benefit firms in other sectors (e.g. Keesing, 1967; Feder, 1982; Edwards, 1993).
The existence of these externalities and the role for export promotion, however, are highly
controversial. Advocates of active export promotion policies have used such justifications to
support government intervention. According to Lall (2002), the evidence suggests that export
promotion policies have been effective for improving export performance in newly industrialized
economies. Skeptics argue that these policies distort competition and undermine the multilateral
free trade system.5
Therefore empirical evidence on this regard is important to evaluate whether these
spillovers exist. Table 1 shows the studies that have studied the existence of spillovers from
exporting. Most of the studies explore potential technological or information spillovers from
5 Panagariya (2000), for example, discusses how traditional and recent arguments fail on theoretical and empirical grounds as justifications for the implementation of selective policies for export promotion, while Rodrik (1999) argues that there is not robust evidence of spillovers emanating from exporting activities.
5
exporters to other firms’ export performance. They analyze how export concentration affects the
probability of exporting and/or export intensity (measured as the export to sales ratio). These
analyses typically focus on firms operating in the same industry and/or region and in some cases
they distinguish between exports by domestic firms from exports by multinational corporations.
These studies either do not find evidence that export activity increases the probability of exporting
(e.g. Clerides et al., 1998; Barrios et al., 2003; Bernard and Jensen, 2004a) or find that only
multinational exporters generate spillovers (e.g. Aitken et al., 1997; Greenaway, et al., 2004;
Ruane and Sutherland, 2004). The effect of exporting activity on export intensity of exporters is
also not clear. While some find a positive effect of exporting activity by multinationals on export
intensity (e.g. Greenaway, et al., 2004) others find a negative effect (e.g. Ruane and Sutherland,
2004).
Table 1 also shows studies that have looked at productivity spillovers from exporting. Most
of them focus on foreign-owned exporters and consider the intra-industry aspect of spillovers. Only
Clerides et al. (1998) study the potential productivity spillovers from domestic exporting. But
their results do not provide support for their existence. Using Colombian plant-level data they find
that high export activity is not, in general, associated to lower production costs. In fact, in some
cases exporting appears to increase costs of production. As seen in the table, none of the studies
looks for spillover across sectors from domestic exporters through buyer-seller relationships. There
are several ways by which exporters may affect their suppliers (backward spillovers). They may
transfer knowledge and technically assist firms in upstream industries, so they can satisfy higher
quality requirements in foreign markets. In addition, an expansion of export industries may
increase the demand, or generate new demand, for intermediate inputs in upstream sectors.6
6 In Chile this seems to be the case with recent expansions in exports of wine and salmon. Once these industries maturated, there was a growing demand for specialized inputs.
6
There are also arguments favoring the existence of forward export spillovers. This would be
the case when downstream industries may become more productive as a result of gaining access to
new, improved, or less costly intermediate inputs. Although these spillovers have been commonly
associated to the presence of multinationals, there are no reasons to disregard that exporters may
be responsible for the same phenomenon. Consider, for example, the Chilean case of fruit exports.
Fruit is raw material for production of juice, canned fruit, and other more elaborate products. It is
reasonable that technological advances in industries producing the input or the introduction of a
new variety (raw fruit) may have an important effect on downstream industries (juice, canned
fruit).
The arguments presented in this section refer to positive spillovers. Theoretical
considerations, however, prevent us of being too optimistic. First, horizontal spillovers may be
unobserved in practice because firms have incentives to prevent information flows to competitors.
Second, export expansion in some regions or industries may increase the cost of labor or of other
specialized inputs. In these cases, the net spillover effect may be ambiguous. The net effect on
plant productivity then depends on the balance between the positive effect provided by
technological transfer and the negative effect of increased competition on input prices and the
scale of production.7
7 This negative effect has been denominated “congestion.” Evidence on this regard has been found by Karpaty and Kneller (2006) for the entry of multinationals in Sweden.
7
3. Data and Econometric Strategy
3.1 Data
The empirical analysis is based on the Annual National Industrial Survey (ENIA) carried out by
the National Institute of Statistics of Chile (INE) for the years 1990 through 1999. This survey
covers the universe of Chilean manufacturing plants with 10 or more workers. A plant is not
necessarily a firm; however, a significant percentage of firms in the survey are actually single-plant
firms (Pavcnik, 2002). The INE updates the survey annually by incorporating plants that started
operating during the year and excluding those plants that stopped operating for any reason.
For each plant and year, the ENIA collects data on production, value added, sales,
employment and wages (production and non-production), exports, investment, depreciation,
energy usage, foreign licenses, and other plant characteristics. In addition, plants are classified
according to the International Standard Industrial Classification (ISIC) rev 2. Using 4-digit
industry level price deflators, all monetary variables were converted to constant pesos of 1985.
Plants do not report information on capital stock, thus it was necessary to construct this variable
using the perpetual inventory method for each plant.
3.2 Econometric Strategy
We study the role of productivity spillovers from export activities by considering an augmented
production function which explicitly incorporates the role of spillovers:
(1) 10 1 2 3 2
3
ln( ) ln( )
+ ln( )
NP Pijrt ijrt ijrt ijrt jt jt
jt ijrt
y k l l Horizontal Backward
Forward
α α α α β ββ ε
= + + + + + +
+,
8
where ijrty is the log of value added of plant i operating in sector j and region r at time t; ijrtk is
the log of plant’s capital stock, while NPijrtl and P
ijrtl are the logs of non-production and production
labor respectively. The horizontal spillover variable for a given industry, say j, is defined as the
exports to sales ratio of that industry:
(2) ijt
i jjt
ijti j
ExportsHorizontal
Sales∈
∈
=∑∑
.
Thus, we are assuming that the larger the share of exports in a given industry, the larger
the potential spillover effect. The Backwardjt variable is a proxy for the export orientation of
industries that are supplied by industry j:
(3) ,
jt jk ktk k j
Backward Horizontalα≠
= ∑ ,
where jkα is the proportion of sector j’s output supplied to sector k. We calculate these
coefficients using data from the input-output matrix of Chile, constructed by the Central Bank of
Chile, at the 3-digit ISIC level for the year 1996. Given that we are interested in linkages within
the country and across productive sectors, we exclude the output for final consumption as well as
the imports of intermediate products. Finally, the Forwardjt variable attempts to measure the
export orientation of industries that supply inputs to industry j:
(4) ,
jt jk ktk k j
Forward Horizontalσ≠
= ∑ ,
where jkσ is the share of inputs purchased by industry j from industry k in total inputs purchased
by industry j.
Figure 1 shows the average value for the period 1990-1999 of the horizontal variable at the
3-digit sector level. As can be seen, the most export-oriented sectors are basic chemicals (351),
non-ferrous metals (372), paper (341), wood (331), and iron and steel (371), while sectors such as
9
non-metallic products (369), petroleum products (353, 354), plastic (356), and professional
equipment (385) export a very low fraction of their output.
Figures 2 and 3 show the backward and the forward variables, respectively. There are
important differences across industries. For example, the backward variable, which measures the
average export orientation of sectors that are supplied by the given industry, is high in ceramics
and glass (361, 362), plastic (356), and basic chemicals (351), but very close to zero for transport
equipment (384), footwear (324), and rubber products (355). The forward variable, which
measures the export orientation of sectors that provide inputs to the given industry, also varies
across sectors. High values are observed in printing (342), furniture (332), metal products (381),
leather products (323), and beverages (313), while low numbers are found in iron and steel (371),
non-ferrous metals (372), and wood products (331).
For estimation purposes, it will be convenient to re-write equation (1):
(5) 11 2 3 0 2
3
ln( ) ln( )
+ ln( )
NP Pijrt ijrt ijrt ijrt jt jt
jt ijrt
y k l l Horizontal Backward
Forward
α α α α β ββ ε
− − − = + + +
+.
The left-hand side of this equation is the traditional measure of the log of total factor
productivity (TFP) at the plant level. To measure TFP we estimate a Cobb-Douglas production
function for each 3-digit level industry using the method proposed by Olley and Pakes (1996) and
later modified by Levinsohn and Petrin (2003a, 2003b), which corrects the simultaneity bias
associated with the fact that productivity is not observed by the econometrician but it may be
observed by the firm (see Appendix for more details). The residuals of these regressions correspond
to our measures of productivity. Once TFP has been measured, we estimate the following
equation:
(6) 10 2 3ln( ) ln( ) ln( )ijrt jt jt jt ijrtTFP Horizontal Backward Forwardα β β β ε= + + + + .
10
There are several estimation issues that need discussion. First of all, there may be
unobserved plant characteristics which make some plants more productive. In that case the error
term in equation (6) can be decomposed into ijrt i ijrtc uε = + , where ic is the unobserved plant-
specific effect, and ijrtu is an error term. Then (6) becomes:
(7) 10 2 3ln( ) ln( ) ln( )ijrt jt jt jt i ijrtTFP Horizontal Backward Forward c uα β β β= + + + + + .
In the estimation, we treat ic as fixed effects and use OLS to estimate the parameters of
the within transformation of (7). Since there may be also sector, region, and year specific effects
that affect productivity we add a full set of 3-digit sector, region, and year dummy variables.
A second issue is that we need to control for the geographic concentration of the industry.
Suppose, for example, that plants tend to agglomerate in some sectors and regions.8 These
agglomeration effects may make plants that operate in that industry/region more productive and,
if the sector is also exporting a high fraction of their output, we may erroneously conclude that
exporting increases productivity of the plants. To control for this possibility, we include a measure
of the geographic concentration of the economic activity in the sector/region. We use two
measures of concentration:
Concentration 1
rjt
jtrjt
rt
t
EmploymentEmployment
EmploymentEmployment
⎛ ⎞⎜ ⎟⎝ ⎠=⎛ ⎞⎜ ⎟⎝ ⎠
,
and
Concentration 2
rjt
jtrjt
rt
t
Gross OuputGross Output
Gorss OutputGross Output
⎛ ⎞⎜ ⎟⎝ ⎠=⎛ ⎞⎜ ⎟⎝ ⎠
.
8 See Head and Mayer (2004) for a survey on agglomeration and trade.
11
A third estimation issue is a possible endogeneity of the spillover variables. Suppose, for
instance, that some sectors export more because the plants that operate in that sector are more
productive. Furthermore, some plants may increase their productivity with the purpose of
becoming exporters (Halward-Driemeier et al., 2002; López, 2005). Similarly, more productive
plants may self-select and supply inputs to sectors with a high export orientation. In these cases
the error term in equation (7), ijrtu , will be correlated with the spillover variables, so that the OLS
estimates will be inconsistent. To address this problem, we use the method of instrumental
variables. We instrument our three spillover variables using sector-level real exchange rates. We
assume that the level of the real exchange rates is correlated with the export shares but not with
variables other than exports that affect productivity (the error term in equation (7)). We argue
that this is a reasonable assumption for two reasons. First, there is plenty of evidence that
variations in real exchange rate are associated with significant changes in exports.9 Second, it
seems hard to argue that measures of real exchange rate at the industry-level can affect a variable
such as productivity that is measured at plant-level. Following recent models of firm heterogeneity
and international trade, we may expect a positive relationship between real exchange rate and
industry average productivity, but not for individual plants’ productivity. In fact, a real
depreciation may be thought of as a reduction in trade costs, which according to Melitz (2003) and
Bernard et al. (2006), raises the level of competition and the aggregate productivity of the
industry.
We construct three real exchange rates indices. The first one (RERjt) is a weighted average
of the bilateral real exchange rates between Chile and the 15 main destination countries of the
Chilean exports of the industry:
9 Recent evidence by Bernard and Jensen (2004b) show that real depreciations increase the export share of US plants in the manufacturing sector.
12
1
C
jt cj ctc
RER RERθ=
=∑ ,
where RERct is the bilateral real exchange rate between Chile and country c;10 C=15 is the number
of countries; and θcj is defined as:
1
1 Tcjt
cjt jt
ExportsT Exports
θ=
= ∑ ,
where Exportscjt is the value of exports from industry j to country c at time t; Exportsjt is the
value of exports from industry j at time t; and T is the number of periods trade data is available
(9 years, from 1991-1999). This index is assumed to be correlated with the export share of the
sector (the Horizontal variable).
The other two instruments measure the real exchange rate that exporters face in upstream
sectors (RER-Backwardjt) and the real exchange rate faced in downstream sectors (RER-
Forwardjt). They are defined following equations (3) and (4):
,jt jk kt
k k j
RER Backward RERα≠
− = ∑ , and
,jt jk kt
k k j
RER Forward RERσ≠
− = ∑ ,
where we are assuming that the higher the real exchange rate that exporters face in downstream
and upstream sectors, the higher the export share of those sectors.
We use these instruments to obtain predicted values of our three spillover variables, which
are then used to estimate the effect of exporting on plant productivity. The real exchange rates
turn out to be highly correlated with export shares at the sector level. A simple regression between
industries’ export share and real exchange rates, both in logs, gives us a coefficient of 1.34 and a t
10 The bilateral real exchange rate between Chile and country c is: RERct=NomERct*Pct/PChile,t. NomERct is the nominal exchange rate between Chile and country c (Chilean pesos / country’s c currency), while Pct and PChile,t are producer price level indices for country c and Chile, respectively. The nominal exchange rates and producer prices were obtained from the International Financial Statistics of the International Monetary Fund. In cases in which the producer price was not available the consumer price index was used.
13
statistic of 7.68. In order to check the validity of these instruments, we follow the traditional
procedures of looking at the individual t statistics for the coefficients of the three measures of
exchange rates, and the F statistics for the model including all the exogenous variables. The first-
stage regressions confirm that our instruments are adequate. The t statistics for the coefficient of
real exchange rates reveal that these variables are always significant at 1%. A more formal test is
the Anderson-Rubin test of the significance of the endogenous regressors.11 The null hypothesis
tested is that the coefficients of the endogenous regressors in the structural equation are jointly
equal to zero, and is numerically equivalent to estimating the reduced form of the equation (with
the full set of instruments as regressors) and testing that the coefficients of the excluded
instruments are jointly equal to zero. In all our estimations, the null hypothesis is rejected at 1%,
confirming the validity of our instruments.12 Figures 4, 5, and 6 are scatterplots of the true
spillover variables against their predicted values. These figures show that the real exchange rate
accounts for most of the variation in the export shares.
Table 2 shows descriptive statistics for all the relevant variables. There are 49,106 plant-
year observations, but after eliminating the ones for which we could not estimate TFP, we end up
with 40,476 observations.
4. Results
4.1 Basic Results
Table 3 reports our basic results of estimating equation (7). The first three columns of numbers
are the plant fixed effects estimates without taking into account the endogeneity problem. Column 11 This is different from Anderson-Rubin test for overidentifying restrictions. In our case, the model is exactly identified because we have three endogenous regressors and three excluded instruments. 12 The same conclusion is reached when we use as an alternative test of weak identification the Cragg-Donald test. All of these tests for first step regressions are generated by the command xtivreg2 in Stata.
14
(1) shows that the coefficient on backward and horizontal are positive, although only backward is
statistically significant. A 1% increase in the ratio exports/sales in downstream industries increases
productivity of plants in upstream industries in 0.291%, on average. Thus, sectors with higher
exports increase the productivity of plants that provide inputs to those sectors but do not increase
the productivity of plants that operate in the same industry. The forward variable is negative but
not significant. In columns (2) and (3) we control for the industry/region concentration of
economic activity. The labor concentration (concentration 1) is not significant and does not
change the estimates. The output concentration (concentration 2) is positive and statistically
significant suggesting that there may be some positive agglomeration externalities. The coefficients
for the spillover variables remain the same and the forward variable becomes marginally significant
at 10%.
In column (4) of Table 3 we present the estimates using the IV method with plant fixed
effects. All estimates are higher than the OLS estimates and now the horizontal variable is
statistically significant. A 1% increase in the exports/sales ratio increases productivity of plants in
the same industry by 0.05%, while productivity of plants in upstream industries increases by
0.52%. These results are robust to the inclusion of concentration measures (columns 5 and 6). In
sum, our evidence is consistent with the view that exporters provide positive spillovers to their
suppliers and to other plants in the same industry.
Why are the IV estimates higher than the OLS estimates? In our estimations, the export
share is used to proxy for the different ways in which interactions between plants raise
productivity (technical assistance to suppliers, demonstration effects, etc.). The export share is
likely to be correlated with these interactions but this correlation may be not perfect. Thus, in the
presence of measurement errors, OLS are biased downward. In addition, our export data at plant-
level comes from a survey, so the export data at industry-level may not coincide with the actual
15
amount exported. This suggests that the instrumented exports may be better predictors of the
spillover effects.
4.2 Who Generates Spillovers: Foreign-Owned or Domestic Exporters?
For a developing country, like Chile, it is possible that foreign-owned exporters are the main
source of technologies and knowledge. In other words, positive productivity spillovers may be more
likely to occur from exports by foreign-owned plants than from exports by domestic plants. To
analyze this possibility we split our spillover variables into two components: (1) exports by
foreign-owned plants; and (2) exports by domestic plants. Thus, we define the horizontal-foreign
spillover variable as:
ijt ijti j
jtijt
i j
F ExportsHorizontal Foreign
Sales∈
∈
− =∑∑
,
where Fijt is a dummy variable equal to one if plant i belonging to sector j has a positive amount
of foreign ownership at time t. In the same way we define the horizontal-domestic variable
considering exports by domestic plants only. The variables backward-foreign, backward-domestic,
forward-foreign and forward-domestic are defined following formulas (3) and (4).
Table 4 shows the results of estimating (7) using the exports of foreign-owned plants in our
spillover variables. Columns (1)-(3) refer to the case of OLS with plant fixed effects, while (4)-(6)
are the IV estimates with plant fixed effects. In all six cases the estimates for the three spillover
measures are positive and statistically significant, even when a concentration index is included. A
1% increase in the export/sales ratio increases productivity of plants in upstream industries by
0.16%-0.34%, in downstream sectors by 0.09%-0.27%, and in the same sector by 0.10%-0.23%.
16
These results give strong support to the idea that foreign-owned plants generate positive spillover
effects.
As a robustness check, we also estimate the effect of exporting by foreign-owned plants on
productivity of domestic plants only. The results, not presented here, are almost identical to those
in Table 4. This is consistent with the idea that affiliates of multinational corporations generate
positive productivity spillovers to domestic plants.
Do these findings mean that domestic exporters do not generate spillover effects? The
answer can be obtained from Table 5 which presents the estimates by using exports of domestic
plants only. We see that the estimate for backward is always positive and statistically significant.
A 1% increase in exports/sales increases productivity of plants in upstream sectors by 0.24%-
0.49%. For the forward and the horizontal variables the OLS and the IV regressions give slightly
different results. While the estimates for forward are negative in all six cases, they are not
significant when we use IV (columns 4-6). The horizontal variable, on the other hand, is positive
but never significant if we use OLS, and marginally significant at 10% when we use IV estimation.
There is then strong evidence that domestic exporters generate positive productivity spillovers to
their suppliers, some support for spillovers to other plants of the same industry but no evidence
that they benefit their customers.
In sum, our results suggest that positive spillovers are not only associated with a larger
presence of multinational exporters, but also with domestic exporters. In other words, by focusing
exclusively on foreign-owned firms, researchers have been underestimating the role of domestic
exporters in generating positive effects on other plants’ productivity.
17
5. Conclusions
Unlike most studies that have analyzed intra-industry or horizontal spillovers from export
activities, this paper focuses on inter-industry or vertical spillovers through backward (from
potential customers) and forward linkages (from potential suppliers). Anecdotal evidence suggests
that vertical spillovers, at least from exporters to their suppliers, may be important.
Using data from the manufacturing sector of Chile for the period 1990-1999, we confirm the
existence of positive productivity spillovers from exporters to their suppliers. This is evidence of
backward spillovers. We also find evidence that higher exporting activity in a given sector
increases the productivity of the plants operating in that sector. We do not find, however,
evidence of spillovers from exporters to their customers.
When we distinguish between foreign-owned plants exports and domestic plants exports we
discover that foreign-owned exporters generate positive productivity spillovers to their suppliers,
customers, and to other plants in the same industry. This is consistent with the perception that
multinational corporations transfer technologies in developing countries. But this does not mean
than domestic exporters do not improve the performance of other plants. We find strong support
for the existence of backward spillover effects from domestic exporters to their local suppliers and
some evidence that they benefit plants in the same sector.
Although we have been able to address several estimation issues that have plagued
previous studies such as the identification of spillover effects, the simultaneity problem, and the
role of unobserved plant characteristics, we still believe more work and better data are needed to
identify the exact mechanisms by which exporters transfer knowledge and technologies to other
firms operating either in the same industry or in other industries. Ideally, one would like to have
data on individual transactions between an exporter and its supplier and its customers.
18
Appendix: TFP Construction
To compute TFP we estimate a Cobb-Douglas production function separately for each industry.
Specifically, for each 3-digit sector, we estimate the following equation:
(A1) 0 1 2 3NP P
it it it it ity k l lβ β β β ε= + + + + ,
where ity is the log of value added of plant i at time t; itk is the log of plant's capital stock, while
NPitl and P
itl are the logs of non-production and production labor respectively. TFP is defined as:
( )1 2 3exp .NP Pit it it itTFP y k l lβ β β= − − −
If itε is uncorrelated with the right-hand side variables in equation (A1), then the
production function could be estimated using OLS. However, although productivity is not observed
by the econometrician it may be observed by the firm, thus itε is likely to be correlated with the
regressors. Following Olley and Pakes (1996), and Levinsohn and Petrin (2003a and 2003b) we
explicitly consider this endogeneity problem by writing it it itε ω η= + , where itω is the transmitted
productivity component and itη is an error term that is uncorrelated with input choices, and
assuming that ( , )it it it itm m k ω= , where itm is the intermediate input. Levinsohn and Petrin
(2003a) show that this relationship is monotonically increasing in itω , so the intermediate input
function can be inverted to obtain ( , )it it it itk mω ω= . Then, equation (A1) becomes:
(A2) 2 3 ( , )NP Pit it it it it ity l l k mβ β φ η= + + + ,
where 0 1( , ) ( , )it it it it it itk m k k mφ β β ω= + + .
Equation (A2) can be estimated using the procedures discussed in Petrin, Poi, and
Levinsohn (2004). As in Levinsohn and Petrin (2003a), we use consumption of electricity as the
intermediate input that allows the identification of the elasticity of capital.
19
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23
Table 1: Previous Studies on Exporting Spillovers Probability of
Exporting and/or Productivity
Export Intensity From Foreign-Owned Exporters
From Domestic Exporters
Horizontal AHH*, CLT, BGS,
GK, S, GSW, BJ, RS, KK, KP
CLT, GGP, GH CLT
Backward KP J, GGP None
Forward KP GGP None
* Study deals with endogeneity of industry/region export shares. AHH: Aitken, Hanson and Harrison (1997); CLT: Clerides, Lach and Tybout (1998); BGS: Barrios, Görg and Strobl (2003); GK: Greenaway and Kneller (2003); S: Sjöholmm (2003); GSW: Greenaway, Sousa and Wakelin (2004); BJ: Bernard and Jensen (2004a); RS: Ruane and Sutherland (2005); KK: Karpaty and Kneller (2005); KP: Kneller and Pisu (2005); GGP: Girma, Görg and Pisu (2005); GH: Görg and Hijzen (2004); J: Javorcik (2004).
24
Table 2: Descriptive Statistics
Number of
Observations Mean Std. Dev. Min Max
ln(TFP) 40,476 6.93 1.14 -4.57 12.74 ln(Horizontal) 49,106 -2.43 0.95 -5.70 -0.61 ln(Backward) 49,106 -4.78 1.29 -9.60 -2.90 ln(Forward) 49,106 -3.29 0.74 -5.62 -1.82 ln(Concentration 1) 49,106 0.12 0.68 -5.26 2.81 ln(Concentration 2) 49,106 0.13 0.94 -10.37 3.65 ln(RER) 49,106 4.58 0.15 3.65 4.76 ln(RER-Backward) 49,106 3.29 0.91 -0.37 4.29 ln(RER-Forward) 49,106 3.69 1.15 0.90 4.73 Concentration 1: Labor; Concentration 2: Gross Output.
25
Table 3: Productivity Spillovers from Exporting Plant Fixed Effects IV — Plant Fixed Effects (1) (2) (3) (4) (5) (6) Backward 0.291 0.291 0.291 0.519 0.519 0.527 (3.88)** (3.89)** (3.88)** (4.45)** (4.45)** (4.52)**Forward -0.092 -0.092 -0.094 -0.008 -0.008 -0.018 (1.68) (1.69) (1.72)+ (0.16) (0.16) (0.35) Horizontal 0.034 0.034 0.034 0.053 0.053 0.051 (0.93) (0.93) (0.92) (2.24)* (2.24)* (2.18)* Concentration 1 -0.003 0.002 (0.13) (0.16) Concentration 2 0.068 0.067 (4.20)** (6.27)**Number of Observations 40,476 40,476 40,476 39,648 39,648 39,648 R-Squared 0.183 0.183 0.184 0.177 0.177 0.178 Anderson-Rubin F-Stat 12.49** 12.51** 12.25** Cragg-Donald F-Stat 224.94** 224.94** 224.89** Notes: Absolute value of t statistics in parentheses (z statistics for IV regressions). Standard errors were clustered at the industry level in (1)-(3). Sector, region, and year dummy variables were included but not reported. + significant at 10%; * significant at 5%; ** significant at 1%. Concentration 1: Labor. Concentration 2: Gross Output. All variables in logs.
26
Table 4: Productivity Spillovers from Exporting by Foreign-Owned Plants
Plant Fixed Effects IV — Plant Fixed Effects (1) (2) (3) (4) (5) (6) Backward-Foreign 0.161 0.161 0.161 0.341 0.341 0.329 (3.26)** (3.26)** (3.25)** (4.45)** (4.44)** (4.31)**Forward-Foreign 0.091 0.091 0.091 0.262 0.261 0.266 (2.13)* (2.13)* (2.14)* (4.38)** (4.37)** (4.46)**Horizontal-Foreign 0.104 0.104 0.104 0.226 0.225 0.210 (2.67)* (2.67)* (2.70)* (2.68)** (2.68)** (2.50)* Concentration 1 0.000 0.010 (0.01) (0.65) Concentration 2 0.068 0.068 (4.14)** (6.37)**Number of Observations 40,476 40,476 40,476 39,648 39,648 39,648 R-Squared 0.184 0.184 0.185 0.169 0.169 0.171 Anderson-Rubin F-Stat 12.49** 12.51** 12.25** Cragg-Donald F-Stat 166.03** 166.79** 166.61** Notes: Absolute value of t statistics in parentheses (z statistics for IV regressions). Standard errors were clustered at the industry level in (1)-(3). Sector, region, and year dummy variables were included but not reported. + significant at 10%; * significant at 5%; ** significant at 1%. Concentration 1: Labor. Concentration 2: Gross Output. All variables in logs.
27
Table 5: Productivity Spillovers from Exporting by Domestic Plants
Plant Fixed Effects IV — Plant Fixed Effects (1) (2) (3) (4) (5) (6) Backward-Domestic 0.242 0.242 0.243 0.483 0.483 0.493 (2.97)** (2.98)** (2.98)** (3.78)** (3.77)** (3.86)**Forward-Domestic -0.105 -0.105 -0.107 -0.024 -0.024 -0.033 (2.37)* (2.37)* (2.42)* (0.47) (0.47) (0.65) Horizontal-Domestic 0.003 0.003 0.003 0.040 0.040 0.038 (0.11) (0.11) (0.11) (1.72)+ (1.71)+ (1.65)+Concentration 1 -0.001 0.004 (0.07) (0.26) Concentration 2 0.069 0.069 (4.22)** (6.40)**Number of Observations 40,476 40,476 40,476 39,648 39,648 39,648 R-Squared 0.182 0.182 0.183 0.174 0.174 0.175 Anderson-Rubin F-Stat 12.49** 12.51** 12.25** Cragg-Donald F-Stat 156.68** 155.82** 156.39** Notes: Absolute value of t statistics in parentheses (z statistics for IV regressions). Standard errors were clustered at the industry level in (1)-(3). Sector, region, and year dummy variables were included but not reported. + significant at 10%; * significant at 5%; ** significant at 1%. Concentration 1: Labor. Concentration 2: Gross Output. All variables in logs.
28
Figure 1: Horizontal Spillover Variable, 1990-1999
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
311 312 313 321 322 323 324 331 332 341 342 351 352 353 354 355 356 361 362 369 371 372 381 382 383 384 385 390
Figure 2: Backward Spillover Variable 1990-1999
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.040
0.045
0.050
311 312 313 321 322 323 324 331 332 341 342 351 352 353 354 355 356 361 362 369 371 372 381 382 383 384 385 390
Figure 3: Forward Spillover Variable 1990-1999
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
311 312 313 321 322 323 324 331 332 341 342 351 352 353 354 355 356 361 362 369 371 372 381 382 383 384 385 390
29
-6-4
-20
Hor
izon
tal
-5 -4 -3 -2 -1Predicted Horizontal
Figure 4: Actual vs. Predicted Horizontal Variable (In Logs)
-10
-8-6
-4-2
Bac
kwar
d
-10 -8 -6 -4 -2Predicted Backward
Figure 5: Actual vs. Predicted Backward Variable (In Logs)